1. In 2010 (most recent year available), the top 400 taxpayers based on Adjusted Gross Income earned $106 billion collectively, and they paid $19.1 billion in federal income taxes at an average tax rate of 18% (see chart above).

2. In 2010, the bottom 50% of taxpayers, a group totaling 67.5 million Americans, earned collectively almost $1 trillion and paid $22.4 billion in federal income taxes at average tax rate of 2.4% (see chart above).

Bottom Line: A small group of 400 of America’s most successful earners in 2010, about the number of residents living in a typical apartment building in Washington, D.C., paid almost as much in federal income taxes as the entire bottom half of America’s 135 million tax filers, which is a population equivalent to the combined number of residents living in America’s 29 least populated states, plus the District of Columbia. What makes this disparity possible is the fact that 41% of individual income tax returns filed in 2010 had a zero or negative tax liability, according to The Tax Foundation. And a recent CBO study (featured on CD here) found that the entire bottom 60% of American households are “net recipient households” and received more in government transfers than they paid in federal taxes in 2011.

When you have only 400 Americans paying almost as much in federal income taxes as the entire bottom 50% of Americans filing income tax returns, I think we can dismiss any notion of the rich not paying their “fair share” of taxes. In fact, maybe the IRS should publish the names and addresses of the Top 400 taxpayers (or provide a forwarding service to protect anonymity), so that we can all send them “Thank You” letters to express our gratitude for shouldering such a disproportionately large share of our collective tax burden.